During a recent field trip to the Caribbean island of Montserrat, two members of Kew staff discovered plant species which had not previously been known to occur on the island.
Marcelo Sellaro, a bromeliad specialist from Kew's Horticulture Department, and Anna Haigh, a botanist with a special interest in aroids, recently returned from a field trip to Montserrat, one of the UK Overseas Territories (UKOTs). Although Kew's UKOT's team have been involved in botanical assessments of parts of the island during the last decade, there is always more to learn about Monserrat's plants, both native and introduced. During this visit, Marcello and Anna were able to add several plants to the list of species found on the island.
Marcelo collecting seed
Montserrat's plant diversity
The Caribbean region has been identified as one of 34 global biodiversity hotspots due to its plant-species richness as well as high levels of endemism (plants unique to the area). A recent inventory of plant species on Montserrat, carried out by Kew's UKOTs team, listed as many as 800 native species, including many species of limited global distribution and several which are globally threatened. Its botanical riches are paralleled in the diversity of its fauna.
Approximately 5000 people currently live on Montserrat, and although the island has a total area of 102 km², the distribution of both people and wildlife is severely limited by volcanic activity in the south of the island. In 1995 there was an eruption of the previously dormant Soufriere Hills volcano, and it is still active today but on a much reduced scale. A great deal of vegetation in the south of Montserrat has been destroyed by volcanic activity, resulting in the loss of 60% of the island’s forest cover. Montserrat has very interesting areas where secondary forests show how nature can create new environments after devastation caused by human activity and natural events, such as volcanoes and hurricanes. There are trails in the Centre Hills which provide access through the forest, enabling residents and visitors to explore the area. The Centre Hills are recognised as one the most valuable sources of income for the island, primarily through tourism, but also as a source of ash for the concrete industry.
Montserrat has a humid tropical climate with a wet season from July to December. Annual rainfall varies from 1100 mm at the coast to 2100 mm at higher elevations. In lowland areas that receive little rain, the vegetation is dominated by dry scrub, which may be replaced by littoral forest in coastal areas affected by sea spray. Mesic Forest is a forest type between Dry Forest and Wet Forest where water availability allows for the development of denser vegetation than at lower elevations. It contains a wide range of species and a well developed forest structure. It also supports a wide range of epiphytes (plants which rely on host trees for support) and climbing plants, such as bromeliads (members of the pineapple family - Bromeliaceae) and aroids (belonging to the Araceae family which includes the British plant lords-and-ladies - Arum maculatum). As altitude increases, the Wet Forest gives way to Elfin Woodland, a densely shrubby vegetation with a canopy 0.5–3 m in height. This habitat is restricted to the highest peaks of the Centre Hills.
Anna descending through wet forest in the Centre Hills
Finding out about Montserrat's plants
The Centre Hills Biodiversity Assessment was published in 2008. Kew's UKOTs team was responsible for the checklist of plants - they also made herbarium specimens - and this data helped us as a guide to find the bromeliads and aroids. This checklist contained eight species of Araceae, and Herbarium specimens collected prior to 2008 contained 11 species of Bromeliaceae from Montserrat. Most of the information available from Kew's Herbarium dates from 1907 and 1966 and is not very precise regarding localities and plant descriptions. It is interesting to note that many bromeliads and aroids were previously found on Chance’s Mountain. Today this area is completely covered by ash from the volcano in the Soufriere Hills. The most similar environment on the island, disturbed by agriculture in the past, is the Centre Hills, which are today protected by the government as a reserve.
There are several reasons why aroids are often overlooked during collecting. Some species flower only rarely and we were looking for these fertile specimens as these are usually required for accurate identifications. Aroids often have large leaves and are awkward to make good specimens from. They are very slow to dry, losing much information in the process, thus requiring very good field notes! And quite often aroids are found high up in trees out of reach.
Aroid leaves are big and bulky to collect and dry. In the distance the land surface is covered with volcanic ash.
What we found
During 12 days of field work with colleagues from the Montserrat National Trust (MNT) and the Environmental and Forestry Department, covering five different trails on the island, seven specimens of bromeliads plus nine aroids were found on this trip. This enabled us to add to the national checklist, living collections at the MNT, and to duplicate collections for ex situ conservation by seeds and cuttings at Kew. We first saw Pitcairnia angustifolia at sea level, growing on rocks. Later on, grassy clumps of this species with huge inflorescences full of red hooded flowers were found everywhere on the island. The spines on the leaf margins, the type of inflorescence, number of flowers and colour are important characters for identification in Bromeliaceae and the variations we observed lead us to believe that this species has natural hybrids or varieties which have never before been described by botanists. Tillandsia utriculata, found from sea level to 1200 m altitude, is widely distributed and mostly grows as an epiphyte. Being a truly monocarpic species (which dies after flowering), it depends completely on seeds for survival and we were surprised to find a plant with a secondary inflorescence growing on the side. Epiphytic and sometimes terrestrial in dry habitats, we found Tillandsia recurvata in the Dry Forest where there is little or no rainfall. It also occurred close to the sea where plants need to tolerate winds and salt spray.
Tillandsia recurvata growing on trees close to the seashore
Support for native plant conservation
Both aroids and bromeliads are attractive plants for horticulture. The Botanic Gardens on Montserrat is interested in promoting knowledge about native plants and also needs to provide an attractive garden. It contains an area that mimics the ghauts (steep-sided valleys) where water flows in the rainy season. In the arboretum, trees have created shady areas for recreation and could be used as support for native epiphytes and climbers. We gave a workshop at the Botanic Garden at the end of our trip, which was very successful. About 20 people from the MNT, Environmental and Forestry Department and the local community participated in the workshop, which was divided into three topics. We started by giving a talk about the botanical families, bromeliads and aroids, followed by activities involving identification and classification (taxonomy) and then practical cultivation, finishing with a discussion of cultivation practices.
- Anna and Marcelo -
A biodiversity assessment of the Centre Hills, Montserrat(Durrell Conservation Monograph, 2008)
UKOTs bloggers (left to right): Sara Bárrios, Pat Griggs, Colin Clubbe, Marcella Corcoran, Tom Heller, Martin Hamilton.
Using modern plant specimens collected in the field and historic specimens held in Kew’s Herbarium, together with detailed habitat descriptions and other field information, we are documenting the plant diversity of the UKOTs. We are making this information accessible via the UKOTs Online Herbarium. This resource, together with the field research, enables us to undertake conservation assessments, produce Red Lists of threatened species, and rank potentially invasive species – all of which underpin the development of management plans to protect the UKOTs’ plant heritage.
The UKOTs bloggers are:
- Colin Clubbe (Head of UKOTs and Conservation Training)
- Martin Hamilton (UKOTs Programme Co-ordinator)
- Marcella Corcoran (UKOTs Programme Officer – Horticultural Liaison)
- Sara Bárrios (UKOTs Programme Officer – GSPC Targets 1&2 OTEP Project)
- Pat Griggs (UKOTs Public Engagement Officer)
- Tom Heller (UKOTs Millennium Seed Bank Officer)
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